As is well known, the velocity and the position of a servo motor can be controlled precisely. Consequently, servo motors have been widely used in various industrial automation industries and precision machining fields. For example, plural servo motors can be applied to mechanical arms or mechanical work platforms in order to provide multi-dimensional operations.
FIG. 1 is a schematic functional block diagram illustrating the architecture of a servo motor system. As shown in FIG. 1, the servo motor system 115 comprises a driver 120, a servo motor 130 and an optical encoder 140.
In response to the user's operation, a control device 110 issues a command pulse wave to the servo motor system 115 for controlling the velocity and the rotation direction of the servo motor 130. The servo motor system 115 is a close-loop control system. According to the command pulse wave and a feedback pulse wave, the driver 120 generates a driving current to the servo motor 130 in order to control the velocity and the rotation direction of the servo motor 130.
Moreover, according to the velocity and the rotation direction of the servo motor 130, the optical encoder 140 generates the feedback pulse wave to the driver 120. The optical encoder 140 is a feedback device. Alternatively, the optical encoder 140 may be replaced by any other appropriate device such as a resolver.
After the servo motor system 115 is installed on a mechanical arm or a mechanical work platform, the mechanical arm or the mechanical work platform can perform a one-dimensional operation according to the command pulse wave from the control device 110.
In case that three servo motor systems as shown in FIG. 1 are installed on a mechanical arm or a mechanical work platform, the mechanical arm or the mechanical work platform can perform a three-dimensional operation. In other words, the mechanical arm or the mechanical work platform performs the three-dimensional operation according to the command pulse waves from three control devices.
Therefore, there is a need of providing a method for immediately generating the command pulse wave and accurately controlling the velocity and position of the servo motor.